Battery packs are used in a variety of types of electronic devices such as radios, portable computers, telephones, and cameras. Rechargeable battery packs, such as lithium-ion, nickel-cadmium, nickel-metal hydride, and other types of rechargeable batteries, are favored by users over non-rechargeable batteries, such as alkaline batteries, to provide longer energy life, lighter weight, and less cost. However, rechargeable batteries are generally sensitive to overcharging, overdischarging, and/or exposure to excessive current loads. For example, contaminants in the battery pack, a loose or failed battery pack component, and/or an excess current load may cause an excessive thermal energy condition in the battery pack. The excessive thermal energy condition may also migrate to the cells of the battery pack, thereby posing a significant safety hazard.